code: def grammar(self) -> Optional[Grammar]:
      # grammar: metas rules | rules
      mark = self._mark()
      if (metas := self.metas()) and (rules := self.rules()):
          return Grammar(rules, metas)
      self._reset(mark)
      if rules := self.rules():
          return Grammar(rules, [])
      self._reset(mark)
      return None
  
imports: import ast
  import sys
  import tokenize
  from typing import Any, Optional
  from pegen.parser import memoize, memoize_left_rec, logger, Parser
  from ast import literal_eval
  from pegen.grammar import Alt, Cut, Forced, Gather, Group, Item, Lookahead, LookaheadOrCut, MetaTuple, MetaList, NameLeaf, NamedItem, NamedItemList, NegativeLookahead, Opt, Plain, PositiveLookahead, Repeat0, Repeat1, Rhs, Rule, RuleList, RuleName, Grammar, StringLeaf
label_desc: Use image node_id 2 for calling the GeneratedParser obj's underlying member method code with example usage: obj.grammar() and returns: None, Grammar, Grammar